Walter Donaldson was born on February 15, 1893 in Brooklyn, New York. One of eleven children in a music-loving family, his early musical talent bloomed under the tutelage of his mother, a classically trained pianist and teacher. As a boy he wrote songs for school productions, demonstrated sheet music in five and ten cent stores, worked as a pianist in neighborhood nickelodeons and at a Brighton Beach hotel. After a brief flirtation with the world of finance and Wall Street, Donaldson began his professional music career as a staff pianist in Tin Pan Alley.

In 1915 he wrote his first hit songs, and continued to write throughout his enlistment in the army during the First World War, frequently entertaining the troops and at War Bond Rallies. Along the way, Donaldsons songs were regularly featured in Vaudeville and many shows.